安装
yarn add koa
代码
Koa的核心代码就三行
const app = new Koa()
app.use(middleware)
app.listen(3000)
const Koa = require('koa')
const app = new Koa()
app.use(async (ctx, next) => {
ctx.body = 'Hello World!'
})
app.listen(8080)
至此一个简单的服务器运行成功。
koa脚手架
npm install -g koa2-generator
koa2 koa-demo
编写一个静态页面
module.exports = `
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Koa Server HTMl</title>
<link href="https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.bootcss.com/jquery/3.2.0/jquery.min.js"></script>
<script src="https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/js/bootstrap.bundle.min.js"></script>
</head>
<body>
<div class="container">
<div class="row">
<div class="col-md-8">
<h1>Hi Susan</h1>
<p>This is a test</p>
</div>
<div class="col-md-4">
<p>测试静态 HTML 页面</p>
</div>
</div>
</div>
</body>
</html> `
const Koa = require('koa')
const app = new Koa()
const {normal} = require('./tpl/index')
app.use(async(ctx, next) => {
ctx.type = 'text/html;charset=utf-8;'
ctx.body = normal
})
app.listen(8080)
编写模板页面
安装pug模板引擎
yarn add pug
动态模板引擎代码
module.exports = `
doctype html
html
head
meta(charset='utf-8')
meta(name='viewport=', content='width=device-width, initail-scale=1')
title Koa Server Pug
link(href='https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css',rel='stylesheet')
script(src='https://cdn.bootcss.com/jquery/3.2.0/jquery.min.js')
script(src='https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/js/bootstrap.bundle.min.js')
body
.container
.row
.col-md-8
h1 Hi #{ name }
p This is a test
.col-md-4
p 测试动态PUG模板引擎 `
js代码
const Koa = require('koa')
const app = new Koa()
const pug = require('pug')
const {pugTpl} = require('./tpl/index')
app.use(async(ctx, next) => {
ctx.type = 'text/html;charset=utf-8;'
ctx.body = pug.render(pugTpl, {
name: 'Susan'
})
})
app.listen(8080)
使用模板引擎中间件，支持ejs，pug
koa-views
pug模板引擎代码
doctype html
html
head
meta(charset='utf-8')
meta(name='viewport=', content='width=device-width, initail-scale=1')
title Koa Server Pug
link(href='https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css',rel='stylesheet')
script(src='https://cdn.bootcss.com/jquery/3.2.0/jquery.min.js')
script(src='https://cdn.bootcss.com/bootstrap/4.0.0-beta.2/js/bootstrap.bundle.min.js')
body
.container
.row
.col-md-8
h1 Hi #{ name }
p This is a test
.col-md-4
p 测试动态PUG模板引擎
js代码
const Koa = require('koa')
const app = new Koa()
const views = require('koa-views')
const {resolve} = require('path')
app.use(views(resolve(__dirname, './views'), {
extension: 'pug'
}))
app.use(async(ctx, next) => {
await ctx.render('index', {
name: 'Susan'
})
})
app.listen(8080, () => {
console.log('http://localhost:8080')
})
koa-router
yarn add koa-router
代码
const router = require('koa-router')()
router.get('/news', async (ctx, next) => {
ctx.body = '路由'
})
router.get('/news/:id', async (ctx, next) => {
ctx.body = '动态路由'
})
app.use(router.routes())
路由分离
代码
const router = require('koa-router')()
router.prefix('/user')
router.get('/', async ctx => {
ctx.body = 'Hello Koa2'
})
router.get('/info', async ctx => {
ctx.body = 'Hello UserInfo'
})
module.exports = router
const user = require('./routes/user')
app.use(user.routes()).use(user.allowedMethods())
GET
通过ctx.query/ctx.querystring/ctx.request.query/ctx.request.querystring
代码
router.get('/news', async (ctx, next) => {
console.log('ctx.query', ctx.query)
console.log('ctx.querystring', ctx.querystring)
console.log('ctx.request.query', ctx.request.query)
console.log('ctx.request.querystring', ctx.request.querystring)
})
curl i http://localhost:3000/news?name='Susan&age=12'
POST
通过koa-body
const koaBody = require('koa-body')
app.use(koaBody())
router.post('/doAction', async ctx => {
console.log('ctx.request.body', ctx.request.body)
})
curl i http://localhost:3000/doAction -d 'name=Susan,age=20'
静态资源
安装koa-static
代码
const server = require('koa-static')
app.use(server(resolve(__dirname, './static')))
router.get('/', async ctx => {
await ctx.render('index')
})
<link href="css/style.css" rel="stylesheet" /> <img src="img/1.jpg"/> <script src="js/index.js"></script>
Cookie
ctx.cookies.set(name, value, [options]) ctx.cookies.get(name)
如何处理中文
使用Buffer转换
// 将中文转换base64字符串
new Buffer(value).toString('base64')
// 将base64字符串转换为中文
new Buffer(value, 'base64').toString()
Session
安装koa-session
const session = require('koa-session')
app.keys = ['some secret hurr']
const CONFIG = {
key: 'koa:sess',
maxAge: ,
autoCommit: true,
overwrite: true,
httpOnly: true,
signed: true,
rolling: false,
renew: false
}
app.use(session(CONFIG, app))
router.get('/', async ctx => {
let n = ctx.session.view ||
ctx.session.view = ++ n
ctx.body = n
})
Mongodb
https://www.mongodb.com/download-center?jmp=nav#community
操作数据库
http://mongodb.github.io/node-mongodb-native/
安装mongodb
连接数据库，创建集合，插入数据
const MongoClient = require('mongodb').MongoClient
const url = 'mongodb://127.0.0.1:27017' // URL
const dbName = 'dbs' // 数据库名称
const client = new MongoClient(url) // 创建一个Mongodb Client
client.connect(err=>{ // 连接数据库
if (err) return
console.log('Connected successfully to server')
const db = client.db(dbName)
// 插入数据
db.collection('documents').insertMany([
{a:},
{b:},
{c:}
])
db.collection('documents').insertOne(
{d:}
)
client.close()
})
查找数据
db.collection('documents').find({})
.toArray((err, docs) => {
if (err) return
console.log(docs)
})
更新数据
db.collection('documents')
.updateOne({a:}, {$set: {a: }}, (err, res) => {
if (err) return
console.log(res)
})
db.collection('documents')
.updateMany({a:}, {$set: {a: }}, (err, res) => {
if (err) return
console.log(res)
})
删除数据
db.collection('documents')
.deleteOne({a:}, (err, res) => {
if (err) return
console.log(res)
})
Robo 3T
Mongoose
https://mongoosejs.com/docs/api.html
连接数据库
首先配置数据库，创建一个dbs的数据库
module.exports = {
dbs:'mongodb://127.0.0.1:27017/dbs'
}
数据库创建完毕，那么创建model也就是集合，即表
const mongoose = require('mongoose')
let personSchema = new mongoose.Schema({
name: String,
age: Number
})
module.exports = mongoose.model('Person', personSchema)
数据库和表创建完毕，那么开始连接数据库
const mongoose = require('mongoose')
const dbConfig = require('./dbs/config')
mongoose.connect(dbConfig.dbs, {
useNewUrlParser: true
})
此刻数据库连接成功，那么我们开始
添加数据
router.post('/addPerson', async ctx => {
const person = new Person({
name: ctx.request.body.name,
age: ctx.request.body.age
})
let code
try {
await person.save()
code =
} catch (error) {
code =
}
ctx.body = {
code
}
})
查询数据
const res = await Person.findOne({name:ctx.request.body.name})
const ress = await Person.find({name: ctx.request.body.name})
更新数据
const result = await Person.where({
name: ctx.request.body.name
}).update({
age:ctx.request.body.age
})
删除数据
const result = await Person.where({
name: ctx.request.body.name
}).remove()
Redis
访问网页服务器端会在客户端设置cookie保存session
每次请求把cookie中session发送到服务器端
服务端用session保存客户端状态
服务器端会把session的值保存到Redis中
浏览器用cookie保存session
而且Redis是一个非常快速的读写数据库
案例：登录校验
安装
https://github.com/MicrosoftArchive/redis/releases
启动Redis
安装koa中间件操作Redis
yarn add koa-generic-session koa-redis
连接Redis
app.keys=['keys','keyskeys'] // session加密处理，随便两个值
app.use(session({
key:'mt',
prefix:'mtpr',
store: new Redis(),
}))
使用session
ctx.session.count++
我们也可以直接对Redis操作
const Store = new Redis().client
const st = await Store.hset('fix', 'name', Math.random())
使用redis-cli.exe查看数据
key *
get
hset
hget